() \(V_{HRM,max}=\ \frac{2\cdot 0.0025\ cm^{2}s^{-1}}{1.5\ \text{cm}}\ln\left(\frac{1\ K}{0.015\ K}\right)=0.014\ \text{cm\ }s^{-1}\ (50\ \text{cm\ }h^{-1}).\)